1. Field of the Invention
The present invention relates to an ion implantation apparatus.
2. Description of the Related Art
In a certain ion implantation apparatus, an ion source is connected to a power supply thereof such that an ion beam having a small amount of beam current is extracted from the ion source. In this apparatus, the connection between the ion source and the power supply may be modified such that an ion beam having a large amount of beam current is extracted from the ion source.
Another ion implantation apparatus includes an ion source, an acceleration tube, and an electric circuit connecting power supplies thereof, so as to implant ions into a target at high ion energy. The electric circuit is provided with a selector switch for switching the connection so as to implant ions at low ion energy.
Attempts to extend the operating range of the ion implantation apparatus to some degree have been made as described above. However, a realistic proposal to the extension of the operating range beyond the existing categories is rare.
Generally, ion implantation apparatuses are classified into three categories: a high-current ion implantation apparatus, a medium-current ion implantation apparatus, and a high-energy ion implantation apparatus. Since practical design requirements are different for each category, an apparatus of one category and an apparatus of another category may have significantly different configurations in, for example, beamline. Therefore, in the use of the ion implantation apparatus (for example, in a semiconductor manufacturing process), it is considered that apparatuses of different categories have no compatibility. That is, for particular ion implantation processing, an apparatus of a particular category is selected and used. Therefore, for a variety of ion implantation processing, it is necessary to own various types of ion implantation apparatuses.